Non-Isolated Interleaved Hybrid Boost Converter for Renewable Energy Applications

DC-DC boost converters are necessary to extract power from solar panels. The output voltage from these panels is far lower than the utility voltage levels. One of the main functions of the boost converter is to provide a considerable step-up gain to interface the panel to the utility lines. There are several techniques used to boost the low panel voltage. Some of the issues faced by these topologies are a high duty ratio operation, complex design with multiple active switches and discontinuous input current that affects the power drawn from the panel. This paper presents a boost converter topology that combines the advantages of an interleaved structure, a voltage lift capacitor and a passive voltage multiplier network. A mathematical analysis of the proposed converter during its various modes of operation is presented. A 100 W prototype of the proposed converter is designed and tested. The prototype is controlled by a PIC16F18455 microcontroller. The converter is capable of achieving a gain of 10 without operating at extremely high duty ratios. The voltage stress of the switch is far lower than the maximum output voltage.

A Coupled-Inductor Interleaved LLC Resonant Converter for Wide Operation Range

In this paper, a coupled-inductor interleaved LLC resonant converter (CI-ILLC) was proposed, which can achieve extensive operation range applications by multiplexing inductors and switches. In this proposed CI-ILLC, the coupled-inductor not only serves as a filter inductor but also plays the role of transformer to improve the power density. By changing the modulation methods, the proposed converter can work at three modes for a wide operation range, namely high gain (HG) mode, medium gain (MG) mode, and low gain (LG) mode. Moreover, the interleaved structure greatly reduces the current ripple and current stress of switches. Besides, in HG and MG modes, all switches can realize zero-voltage switching, with high energy transmission efficiency. Finally, the simulation and experiment results of the prototype with 120–200 V input and 50–200 V output are presented to verify the viability of the proposed converter.

Predictive control strategy on an the ultra-high gain DC/DC converter suitable for photovoltaic energy conversion system

This paper presents a control scheme based on the predictive control strategy on an ultra-high gain DC/DC converter with two-phase interleaved structure. the proposed converter consists of coupled inductors and a voltage multiplier cell to increase the voltage gain. due to the variations in the input voltage and the load in the photovoltaic system, tracking the input voltage from its reference value and also dividing the current evenly in the interleaved structure are considered as important control objectives. the proposed predictive control scheme is employed to the proposed converter using two internal and external control loops and the use of a second-order luenberger observer. finally, the effectiveness and the desired performance of the proposed predictive control scheme is verified by presenting the simulation results as the real-time validation by MATLAB and ATMEGA16A-PU.

Modular Battery Charger for Light Electric Vehicles

Rapid developments in energy storage and conversion technologies have led to the proliferation of low- and medium-power electric vehicles. Their regular operation typically requires an on-board battery charger that features small dimensions, high efficiency and power quality. This paper analyses an interleaved step-down single-ended primary-inductor converter (SEPIC) operating in the discontinuous conduction mode (DCM) for charging of battery-powered light electric vehicles such as an electric wheelchair. The required characteristics are achieved thanks to favourable arrangement of the inductors in the circuit: the input inductor is used for power factor correction (PFC) without additional elements, while the other inductor is used to provide galvanic isolation and required voltage conversion ratio. A modular interleaved structure of the converter helps to implement low-profile converter design with standard components, distribute the power losses and improve the performance. An optimal number of converter cells was estimated. The converter uses a simple control algorithm for constant current and constant voltage charging modes. To reduce the energy losses, synchronous rectification along with a common regenerative snubber circuit was implemented. The proposed charger concept was verified with a developed 230 VAC to 29.4 VDC experimental prototype that has proved its effectiveness.